JPH08295066A - Apparatus and method for forming image - Google Patents

Abstract

PURPOSE: To reduce a load on communication processing of a video controller by a method wherein only when a specified internal state is changed, an image processing means is informed thereof via a communication means. CONSTITUTION: A CPU of an engine part 25 discriminates whether or not a state change-monitoring command is received from a controller part 26. When the state change-monitoring command is received, a status state specified by the state change-monitoring command is monitored. When a content of the status is changed, a specified state-changed signal is outputted. The controller part 26 specifies the status of which a state change is required to be known in the status of the engine part 25, and the engine part 25 informs the controller part 26 via a video interface 24 that a content of the specified status is changed. Therefore, the video controller part 26 is not required to read out the status by using always a serial communication of the video interface 24, and communication processing for read out can be simplified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for connecting image processing means for generating pixel data and image forming means for forming an image on a recording medium via a communication means.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus forms an image based on a video controller for converting video code data forming an image signal into pixel data and the pixel data from the video controller, and transfers and fixes the image on recording paper or the like. And a printer engine that

Next, a video interface for connecting the video controller and the printer engine will be described. FIG. 11 is an explanatory diagram showing a signal list of the video interface. In the figure, "output" indicates the output from the engine controller to the video controller,
"Input" refers to the input from the video controller to the engine controller.

The / BD signal is a horizontal synchronizing signal in the main scanning direction of the printer engine, and the video controller is / BD.
The video data / VDO signal for one main scanning line is transmitted in synchronization with the falling edge of the signal. The / PPRDY signal is a signal indicating that the power supply is connected to the printer engine, the initialization of the engine controller is completed, and the command status can be communicated with the video controller.

The / RDY signal is a signal indicating that the printer engine is ready for a printing operation in response to a print start command (/ PRNT signal is true) from the video controller. The conditions for this / RDY signal to become true are:
The temperature of the heating roller in the fixing unit is proper (sufficient temperature for fixing the toner image on the paper), the recording paper is not in a jam state, the polygon mirror is rotating normally at the specified rotation speed, and the / BD signal is specified. For example, it is output normally in a cycle.

The / TOP signal is a print synchronizing signal in the sub-scanning direction in the printer engine, and the video controller sets the image writing position in the sub-scanning direction in synchronization with the trailing edge of the / TOP signal. The time from the detection of the leading edge of the recording paper by the paper feed sensor until the recording paper reaches the transfer roller, and the latent image formed on the photoconductor by the laser light reaches the transfer roller by the rotation of the photoconductor drum. The paper feed sensor is arranged so that the time until it reaches is equal. Therefore, when the engine controller detects that the paper feed sensor signal (PFSNS) from the paper feed sensor becomes true, it immediately sets the / TOP signal to true for 1 second.

The / SBSY signal is a level signal indicating that the printer engine is transmitting the status (printer status) to the video controller. The / STS signal is 8-bit serial information transmitted to the engine controller, and this signal is called status.

The / PCLK signal is a synchronous clock for serially transmitting the / STS signal. The / PPOUT signal is a signal indicating to the video controller that the recording paper for which printing has been completed is ejected.

The / CBSY signal is a signal indicating that the video controller is sending a command (command to the engine controller). The / PRNT signal is a signal for the video controller to instruct the printer engine to start the printing operation. However, in the case of continuous printing, it means that the printing operation is continued. /
For the CPRDY signal, power is supplied to the video controller, initialization of the video controller is completed,
This is a signal indicating that command status communication has become possible with the printer controller.

The / VDO signal indicates an image signal to be printed by the printer engine. This image signal is transmitted by converting the image code data received by the video controller from the host computer into dot data.

The / CMD signal is 8-bit unit serial information transmitted from the video controller to the engine controller. The / CCLK signal is a synchronous clock of the serial data when transmitting the / CMD signal.

Next, the structure of commands sent from the video controller to the engine controller by serial communication and status signals from the engine controller to the video controller will be described.

As described above, the command and status information is an 8-bit serial signal. When the 1-byte command information is given from the video controller to the engine controller in synchronization with the / CCLK signal, the engine controller returns the 1-byte status to the video controller. This command includes a status request command for checking the status of the printer engine and an execution command for instructing the printer to perform some operation.

Both the command information and the status information use the 8th bit as a parity bit, and odd parity is added at the time of transmission. The status information returned by the engine controller further uses the first bit as a command error bit. When the command from the video controller is undefined data or a parity error occurs, the first bit is set to " 1 ”and send it back.

FIG. 12 is an explanatory diagram showing an example of the status information when the command error is not detected, that is, when the first bit is "0". FIG. 13 is an explanatory diagram showing status information when an error occurs. When an error occurs, the first bit becomes "1" and the type of error is specified by the second bit to the seventh bit.

The basic status information when no error occurs is returned when the video controller sends "01" as the status request command, and the command error bit (first bit) and the parity bit (8th bit). ) Are included as information.

That is, when the second bit becomes "1", it indicates that the printer engine is ready to receive the PRNT signal. When the third bit becomes "1", it indicates that the printer engine is transporting the recording paper. When the 4th bit becomes “1”, it indicates that a recording paper jam or misprint has occurred in the printer engine, and the print data needs to be retransmitted to the engine controller 23.

When the 5th bit becomes "1", it means that the heating roller in the fixing unit of the printer engine is not in an appropriate temperature, and therefore the weight is being waited.
When the 6th bit becomes "1", it indicates that the printer engine is paused by the pause command from the video controller.

When the 7th bit becomes "1", it indicates that the printer engine is in a defective state that must be repaired by calling a serviceman or operator.

In addition to this, the engine controller 23 can inform the video controller of jams of recording paper, no paper, opening of the front door, fixing failure, motor failure, etc. by a command from the video controller.

[0021]

However, in the above conventional example, since the video controller monitors the state of the printer engine by using serial communication, there are the following problems.

That is, even if the state of the printer engine does not change, the video controller has to constantly perform serial communication in order to monitor a plurality of statuses, and the communication processing becomes a heavy load.

Therefore, an object of the present invention is to provide an image forming apparatus capable of reducing the communication processing load of a video controller for monitoring the state of a printer engine.

[0024]

In order to achieve the above object, an image forming apparatus according to claim 1 of the present invention comprises an image processing unit for generating pixel data, and an image processing unit based on the generated pixel data. An image forming unit that forms an image on a recording medium; a monitoring unit that monitors the internal state of the image forming unit;
In an image forming apparatus provided with a communication unit for transmitting information representing the monitored internal state to the image processing unit, the image processing unit includes an internal state designating unit for designating an internal state of the transmitted information. In addition to the above, the communication unit includes a notification unit that notifies the image processing unit of the change in the designated internal state.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the internal state designating means comprises a monitoring inhibiting means for inhibiting monitoring of a specific state in the internal state. To do.

According to a third aspect of the present invention, in the image forming apparatus according to the first aspect, the internal state designating means comprises a specific state designating means for designating a specific state in the designated internal state. The notifying means notifies when the internal state changes to the designated specific state.

In the image forming method according to the fourth aspect, the pixel data is generated by the image processing means, the image is formed on the recording medium by the image forming means based on the generated pixel data, and the image forming means operates. In an image forming method of monitoring an internal state and transmitting information representing the monitored internal state to the image processing unit, the internal state of the transmitted information is designated by the image processing unit, and the designated internal state is designated. When there is a change in the state, the image processing means is informed accordingly.

[0028]

In the image forming apparatus according to the first aspect of the present invention, the pixel data is generated by the image processing means, the image is formed on the recording medium by the image forming means based on the generated pixel data, and the monitoring means is used. The internal state of the image forming unit is monitored, and when the information representing the monitored internal state is transmitted to the image processing unit by the communication unit, the internal state of the transmitted information is designated by the internal state designation unit. When there is a change in the designated internal state, the notification means notifies the image processing means to that effect.

[0029]

EXAMPLE An example of the image forming apparatus of the present invention will be described. The image forming apparatus of this embodiment is applied to a printer.

[First Embodiment] FIG. 1 is a block diagram showing the electrical construction of a printer according to the first embodiment. In the figure,
Reference numeral 16 denotes a CPU, which receives coded image information (code data) from an external device such as a host computer via an external interface 17 by executing a control program stored in the ROM 19. The received code data is input to the image processing unit 20, and the image processing unit 20 stores the code data in the RAM 21 and analyzes the code data. Further, various settings can be made to the controller unit 26 from an external device such as a host computer via the external interface 17.

Reference numeral 18 is a RAM used as a register or the like. The ROM 22 stores font data corresponding to the value of the code data. The font data corresponding to the code data is read from the ROM 22, the received code data is converted into video data consisting of all dots, and stored in the frame memory 23. To do.

When one page of video data is stored in the frame memory 23, the CPU 16 sends a print command to the engine unit 25 via the video interface 24 and is synchronized with the main and sub-scanning synchronizing signals of the engine unit 25. And sends the video data stored in the frame memory 23 to the engine unit 25. Reference numeral 26 is a controller unit, which is composed of the above 16 to 24.

FIG. 2 is an explanatory view showing the internal structure of the engine section 25. In the figure, reference numeral 1 denotes a printer main body, and in this embodiment, a laser beam printer is shown. Reference numeral 2 is a photosensitive drum for visualizing video data. Three
Is an optical unit, which modulates the laser light by the video data sent through the video interface 24 and scans the photosensitive drum 2 by the rotating polygon mirror.

Numeral 4 is a folding mirror for reflecting the laser light emitted from the optical unit 3, and numeral 5 is a charger for uniformly charging the photosensitive drum 2. A developing device 6 develops the electrostatic latent image on the photosensitive drum 2 into a toner image. A transfer device 7 transfers the toner image on the photosensitive drum 2 to a recording sheet.
A cleaner 8 collects the toner remaining on the photosensitive drum 2 after the transfer.

An upper paper feed roller 10a feeds the paper stored in the upper paper cassette 9a. A lower paper feed roller 10b feeds the paper stored in the lower paper cassette 9b. A paper feed / conveyance roller 11 conveys the fed paper to a transfer position. A paper feed sensor 12 detects the presence or absence of the fed paper. A fixing device 13 fixes the toner image transferred onto the sheet by heating and pressing the toner image. 14
A paper discharge sensor detects the presence of paper discharged from the fixing device 13. Reference numeral 15 is a paper discharge tray. 25a is an engine controller.

FIG. 3 is an explanatory view showing a signal list of the video interface 24. Descriptions of those already described in the section of the related art will be omitted. In this embodiment, a designated state change signal (/ CCHG signal) is added. When the engine unit 25 receives a state change monitoring designation command, which will be described later, from the controller unit 26, the engine unit 25 monitors the designated internal state, and immediately when a change occurs in the internal state,
The CCHG signal is set to true for 10 msec.

FIG. 4 is an explanatory diagram showing a list of states of the engine section 25. The basic status indicated by the status number 0 indicates a state required to start the printing operation of the engine unit 25. The description of each bit has been described in the section of the related art, and thus will be omitted.

For each status of status numbers 1 to 6, the detailed configuration of each bit is omitted, but an operator call indicates that an error that can be recovered by the user of the printer has occurred, and a service call requires repair. The error indicates that an error occurred during the printing operation and the image was defective in the middle.The number of resent sheets is defective when the misprint occurs. The upper paper size indicates the size of the paper contained in the upper paper cassette 9a, and the lower paper size indicates the size of the paper contained in the lower paper cassette 9b.

FIG. 5 is an explanatory diagram showing the format of the status change monitoring designation command sent by the controller unit 26. Two bytes represent one command. The first byte is fixed to 7F (HEX), and the engine unit 25 receives the first byte and recognizes that it is a state change monitoring designation command,
Wait for the second byte. The second byte specifies the status number by a 6-bit binary number excluding the command error bit (MSB) and parity bit (LSB). For example, when specifying the lower paper size (status number 6) status Is 0D (HEX).

The engine unit 25 monitors the value of the status designated by the status change designation command, and when the value changes, sets the / CCHG signal to true (L level) for 10 ms. For example, when the status of the upper sheet size (status number 5) is specified (command 7F (HEX) +
0B (HEX), the / CCHG signal becomes L level for 10 ms each time the paper size of the upper paper cassette changes.

FIG. 6 is a flow chart showing a control process in which the CPU of the engine unit 25 receives the state change monitoring command and monitors the state. In the figure, the controller unit 26
It is determined whether or not a status change monitoring command has been received from (step S111). When the status change monitoring command is received, the status status designated by the status change monitoring command is monitored (step S112). When the content of the status changes, the / CCHG signal is set to the L level for 10 msec (step S113). ).

As described above, the controller unit 26 designates one of the statuses of the engine unit 25 for which the state change is to be known, and the engine unit 25 informs the video interface 24 that the contents of the designated status have changed. By notifying the controller unit 26 via the notification, the controller unit 26 does not need to always read the status using the serial communication of the video interface 24 in order to know the state change, and the communication process for reading can be simplified.

Although the / CCHG signal is pulsed in the above embodiment, the present invention is not limited to this. For example, a / CCHG signal cancel command is provided, and the engine section 25 detects a change and sets the / CCHG signal to true. The configuration may be such that the current state is held and the / CCHG signal is returned to the original state upon receiving the / CCHG signal release command from the controller unit 26.

[Second Embodiment] The printer according to the second embodiment will be described below. Since the configuration and operation of the printer of this embodiment are the same as those of the first embodiment, their description will be omitted. FIG. 7 is an explanatory diagram showing the format of a serial communication status monitoring mask command of the video interface 24 in the printer of the second embodiment.

The status monitoring mask command represents one command with 2 bytes, and is used together with the status change monitoring designation command described in the first embodiment. The first byte of the status monitoring mask command is fixed to 3E (HEX), and the engine unit 25 receives the first byte and recognizes that it is a status monitoring mask command, and waits for the second byte. In the second byte, the mask position is specified by 6 bits excluding the command error bit (MSB) and the parity bit (LSB).

When the mask position designation bit corresponding to each bit of the status is 1 by the state change monitoring designation command, masking for stopping the status change monitoring is performed. When the value is 0, monitoring is continued.

For example, the basic status (status number 0) is designated by the status change monitoring command (command 7F
(HEX) +01 (HEX)), in order to monitor the status change of only the print request (second bit) with the status monitoring mask command, the first byte as a command is 3E
(HEX) The second byte is 3E (HEX).
As a result, when the print request bit changes,
The / CCHG signal becomes L level for 10 msec. On the other hand, even if other bits in the basic status change, / CC
The HG signal remains at H level.

FIG. 8 is a flow chart showing the control processing in which the CPU of the engine unit 25 receives the status monitoring mask command and monitors the status. First, it is determined whether or not a status change monitoring command has been received from the controller unit 26 (step S121). If so, it is further determined whether or not the status monitoring mask command is received from the controller unit 26 (step S122). The data obtained by changing the first bit and the eighth bit of the data of the second byte (see FIG. 7) of the status monitoring mask command to the value 1 is held in the RAM as mask data (step S123).

If the status monitoring mask command is not received in step S122, the data obtained by ORing the status of the status designated by the status change monitoring command and the mask data is monitored, and the content of the data is changed. At this time, the / CCHG signal is set to the L level for 10 msec.

The mask data is 81 (HE
X) so that the status is not masked.

As described above, the status can be monitored for each bit by monitoring masking the status for monitoring the status change for each bit.

[Third Embodiment] Next, a printer of the third embodiment will be described. Since the configuration and operation of the printer of this embodiment are the same as those of the first embodiment, their description will be omitted. FIG. 9 is an explanatory diagram showing the format of a serial communication status designation command of the video interface 24 in the printer of the third embodiment.

The state designation command is represented by 2 bytes and represents one command, and is used together with the state change monitoring designation command described in the first embodiment. The first byte of the status designation command is fixed to 5E (HEX), and the engine unit 25 receives the first byte and recognizes that it is a status designation command, and waits for the second byte. The second byte excludes the command error bit (MSB) and parity bit (LSB) 6
It is designed to specify the status value with bits,
Enter a specific value for the status specified by the status change monitoring specification command.

For example, when the lower paper size status (status number 6) is designated by the status change monitoring command (command 7F (HEX) + 0D (HEX)) and the legal paper size is designated by the status designation command, the first byte is set. 5E (HEX) sends 1C (HEX) at the second byte. As a result, when legal paper enters the lower paper cassette, the lower paper size status becomes 1C (HEX), and the engine unit 25 detects this and sets the / CCHG signal to the L level for 10 msec.

When a paper other than legal paper is placed in the lower paper cassette, the lower paper size status becomes 1C.
Other than (HEX) (for example, 01 (HE
X)), and the / CCHG signal remains at H level.

FIG. 10 is a flow chart showing a control process in which the CPU of the engine unit 25 receives a state designation command and monitors the state. First, it is determined whether or not a status change monitoring command is received from the controller unit 26 (step S131). If received, the controller unit 2
It is determined whether or not the status designation command is received from the CPU 6 (step S132), and if the status designation command is received, the second byte (see FIG. 9) of the status designation command is held in the RAM (not shown) as the designation data (step S132). S13
3).

It is judged whether or not the status designated by the status change monitoring command is equal to the designated data (step S134). If they are equal, the / CCHG signal is set to 10 m.
It is set to L level for sec (step S136).

On the other hand, if the status designation command is not received in step S132, the status of the status designated by the status change monitoring command is monitored (step S135).
When the content of the status has changed, the process proceeds to step S136.

As described above, the controller section 26 changes only when an arbitrary status becomes a specific state.
By informing the signal to, the load on the communication processing of the controller unit 26 can be further reduced.

In the above embodiment, the case where the image forming apparatus is applied to the printer is shown, but it is needless to say that it may be applied to the copying apparatus.

[0061]

According to the image forming apparatus of the first aspect of the present invention, the image processing means generates the pixel data, and the image forming means forms the image on the recording medium based on the generated pixel data. An internal state of the information transmitted by the internal state specifying means when the internal state of the image forming means is monitored by the monitoring means and the information representing the monitored internal state is transmitted to the image processing means by the communication means. When the state is designated and the designated internal state is changed, the notifying means notifies the image processing means to that effect.
The information indicating the change in the internal state of the image forming unit that the image processing unit requires can be easily obtained, and the communication processing load of the image processing unit can be reduced.

According to the image forming apparatus of the second aspect, since the internal state designating means is provided with the monitoring inhibiting means for inhibiting the monitoring of the specific state in the internal state, it is not necessary to monitor the specific state which is not necessary. Thus, the communication processing of the image processing means can be further reduced and the monitoring processing of the image forming means can be reduced.

According to the image forming apparatus of the third aspect, the internal state designating means includes a specific state designating means for designating a specific state in the designated internal state, and the notifying means sets the internal state to be Since the notification is given when the specified state changes, the specific state of the internal state can be arbitrarily designated, and the communication processing of the image processing means can be further reduced.

According to the image forming method of the fourth aspect, the pixel data is generated by the image processing means, the image is formed on the recording medium by the image forming means based on the generated pixel data, and the image formation is performed. In the image forming method of monitoring the internal state of the means and transmitting the information representing the monitored internal state to the image processing means, the internal state of the transmitted information is designated by the image processing means, and the designated state is specified. When there is a change in the internal state, the image processing means is notified of that fact, so that the image processing means can easily obtain the information indicating the change in the internal state of the image forming means, and the communication of the image processing means is possible. The processing load can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an electrical configuration of a printer of a first embodiment.

FIG. 2 is an explanatory diagram showing an internal configuration of an engine unit 25.

FIG. 3 is an explanatory diagram showing a signal list of a video interface 24.

FIG. 4 is an explanatory diagram showing a list of states of the engine unit 25.

FIG. 5 is an explanatory diagram showing a format of a state change monitoring designation command sent by the controller unit 26.

FIG. 6 is a flowchart showing a control process in which the CPU of the engine unit 25 receives a state change monitoring command and monitors the state.

FIG. 7 is an explanatory diagram showing a format of a serial communication status monitoring mask command of the video interface 24 in the printer of the second embodiment.

FIG. 8 is a flowchart showing a control process in which the CPU of the engine unit 25 receives a status monitoring mask command and monitors the status.

FIG. 9 is an explanatory diagram showing a format of a serial communication state designation command of the video interface 24 in the printer of the third embodiment.

FIG. 10 is a flowchart showing a control process in which the CPU of the engine unit 25 receives a state designation command and monitors the state.

FIG. 11 is an explanatory diagram showing a signal list of a video interface.

FIG. 12 is an explanatory diagram showing an example of status information when a command error has not occurred, that is, when the first bit is “0”.

FIG. 13 is an explanatory diagram showing status information when an error occurs.

[Explanation of symbols]

 20 image processing section 24 video interface 25 engine section 25a engine controller 26 controller section

Claims (4)

[Claims] 1. An image processing means for generating pixel data, an image forming means for forming an image on a recording medium based on the generated pixel data, and a monitoring means for monitoring an internal state of the image forming means. An image forming apparatus comprising: a communication unit that transmits the monitored information indicating the internal state to the image processing unit, wherein the image processing unit specifies an internal state of the transmitted information. In addition to the above, the image forming apparatus is characterized in that the communication means includes an informing means for informing the image processing means of a change in the designated internal state. 2. The image forming apparatus according to claim 1, wherein the internal state designation unit includes a monitoring prohibition unit that prohibits monitoring of a specific state in the internal state. 3. The internal state designation means includes a specific state designation means for designating a specific state in the designated internal state, and the notification means changes the internal state to the designated specific state. When notifying, it is notified.
The image forming apparatus described. 4. The image processing means generates pixel data, the image forming means forms an image on a recording medium based on the generated pixel data, and the internal state of the image forming means is monitored, and the monitoring is performed. In the image forming method of transmitting the information representing the specified internal state to the image processing means, the internal state of the information transmitted by the image processing means is designated, and when the designated internal state is changed, An image forming method characterized by notifying the image processing means to that effect.